A dual-function guanidinium scaffold for copper sequestration and redox protection in Wilson disease models

Wilson disease (WD) is caused due to mutations in the copper ATPase gene ATP7B, resulting in accumulation of copper and the consequent disruption of cellular redox balance through reactive oxygen species generation. Current therapies mainly depend on copper chelation to lower metal burden which sometimes also strip copper from cuproproteins and disturb key physiological copper-dependent processes. It also does not directly suppress pathological copper reactivity i.e., free radical generation, a major driver of WD progression. To overcome these limitations, we have rationally designed Gua-Cu-3, a C₃-symmetric guanidinium-based non-toxic molecule that can chelate labile copper without metal stripping from cuproproteins due to moderate binding affinity and it has intrinsic antioxidant activity within a single nanosheet-forming supramolecular self-assembly. Spectroscopic, calorimetric, and computational analyses revealed multivalent copper coordination (K_d = 95.4 μM) while radical-scavenging and hydroxyl-radical inhibition assays revealed redox-regulatory activity. In copper loaded hepatocytes, Gua-Cu-3 reduces ATP7B trafficking from trans-Golgi network, confirming effective intracellular copper sequestration. This was accompanied by a marked reduction in oxidative stress readouts, i.e., translocation of Nrf2 in nucleus and of HO-1 expression, thereby limiting lipid peroxidation and restoration of ER and mitochondrial health. Gua-Cu-3 attenuates oxidative stress in ATP7B-homolog-deficient Caenorhabditis elegans and rescues copper-induced developmental defects in zebrafish, outperforming D-penicillamine, which is currently in use for WD management. These findings establish Gua-Cu-3 with a therapeutic potential that couples-controlled copper sequestration with redox regulation and provides a framework for treating WD and other disorders associated with metal dyshomeostasis and oxidative stress.